GB2440266A

GB2440266A - Marking system with integrated verification and compensation

Info

Publication number: GB2440266A
Application number: GB0713932A
Authority: GB
Inventors: Gary David Stamp; Peter Richard Lisher; Ashley Glenister
Original assignee: QUILL CODING SOLUTIONS Ltd
Current assignee: QUILL CODING SOLUTIONS Ltd
Priority date: 2004-02-17
Filing date: 2004-02-17
Publication date: 2008-01-23
Anticipated expiration: 2024-02-17
Also published as: GB0713932D0; GB2440266B

Abstract

The system monitors the quality of the mark and applies compensation to the marking device (200, fig.2) to ensure the quality of the mark is optimum. The system applies marks (i.e. human or machine readable) by a marking device (200, fig.2) and verifies their integrity (i.e. readability and content) by imaging them with an image capture device (202, fig2). The marking system enclosure is mounted on a stage (207, fig.2) and positioned to produce a mark (206, fig.2) upon items (204, fig.2) as they are placed (205, fig.2) at the marking device. The image device captures an impression of the mark and delivers it to the control system (208, fig.2) makes the appropriate adjustments to the compensation device (201, fig.2) to ensure the quality of subsequent marks. The verifying of the mark identifies regions of non-printed pixels 803 and said compensation device (201, fig.2) repositions the mark such that areas of non-printed pixels coincide with spaces 804, 805 within the mark.

Description

Marking system with integrated verification and compensation.

Background

The present invention relates to field of marking, and particularly but not exclusively, to machine and human readable codes found on food and pharmaceutical packaging including but not limited to, expiry dates and production batch codes.

Within industry in general, there is a requirement to mark products and product packaging with unique identifying codes and information relating to contents, expiry dates and production codes. It is also important that producing such marks does not slow the capacity of the production line.

In the European Union, Directive N 2000/13IEC on labelling, identifies the rules put in place on the labelling of foodstuffs to enable, amongst other things, European consumers to get comprehensive information on the contents and the composition of food products. Further legislation governs the labelling and marking of pharmaceutical packaging to guarantee product integrity and trace ability.

It is critical that products contain the appropriate mark, to identify but not exclusively, content and expiry dates. This is particularly important with pharmaceuticals but also perishable products and products which are required to be traced back to origin of manufacture. In some instances supplying a poorly or inaccurately marked package is likely to incur a fine and possible suspension from supplying such future product.

Prior art marking methods include thermal transfer, laser and inkjet. The mark must be legible, accurate, indelible and machine- readable where appropriate. Many factors affect the quality of the mark and include poor alignment of the marking device, inappropriate media (e.g. ink chemistry) or inadequate maintenance (e.g. cleaning).

Some factors are variable (e.g. ambient temperature, line speed, mark content) and necessitate constant adjustment of the marking system.

Prior art validation systems, deploying image capture techniques, are added to the production line and operate separately and independently to the marking device to check that products have been correctly marked. The complexity of computer algorithms to analyse human and machine-readable marks, often slows the packaging line below its optimum manufacturing speed. In addition, there is a preliminary set up process where the image capture and validation device must first determine character parameters to recognise specific marks.

What is required is an integrated marking, validation and compensation system, that does not slow the production process, and produces the appropriate mark of the highest quality with reproducible results so that subsequently the marks are capable of tolerating the maximum amount of damage and still remain readable. This integrated system should require no preliminary set up process and is tolerant to character variations that are within the set tolerance but identifies marks which fall outside the set tolerance.

Statement of invention

Specific implementations of the present invention aim to provide a marking system in which a product is marked, and an integrated validation system that validates said mark allowing the production line to run at full capacity. The validation system requires no prior character recognition set up and is tolerant to small character shape fluctuations that are acceptable within the packaging rules.

The captured image from the validation system is also used to apply compensation to the marking device such that subsequent marks are produced at optimum quality and extending the operational life of the marking device. In the best mode implementation, marking, validation and compensation are carried out under the control of a single machine containing the marking device, an image capture device and a compensation device.

An operator can immediately review the quality of a marked item by viewing both the mark in an image display window and a quality grade indicator on the visual display device.

In the best mode, a marking, verification and compensation system operates to perform: integrated marking, verification and compensation within the same system; and reading the mark and verifying a mark in a single system; and using the results of verification to apply compensation to a system, in particular a marking device: Other features include: a simple quality grade indicator to display a result of the verification process; and a simple indicator to indicate the stability of the production process.

The marking, verification and compensation are carried out under the control of a common control system. A user interface may be provided, enabling an operator to monitor stages of marking, verification and compensation and to set quality levels below which, items marked would automatically be rejected.

According to a first aspect of the present invention, there is provided an integrated packaging marking system with instantaneous verification and integrated compensation comprising: a marking device for applying a mark to products or their packaging; an image capture device for capturing an image of said mark: a verification device for verifying said mark; the verifying identifying regions of non-printing pixels; a compensation device to influence subsequent marks, thereby repositioning the mark such that areas of non-printing pixels coincide with spaces within the mark; and a common control system for controlling said marking device, said image capture device, said verification device and said compensation device.

According to a second aspect of the present invention, there is provided an integrated method of applying a mark to a package and verifying said mark and applying compensation to subsequent marks, said method comprising: inputting a set of data to create at least one mark; and applying said mark to at least one package or packaging; and capturing an image of said applied mark; and verifying whether said mark is within packaging rules; the verifying identifying regions of non-printing pixels; and applying compensation to marking device, thereby repositioning the mark such that areas of non-printing pixels coincide with spaces within the mark.

The invention includes an interface display for operating a marking, verification and compensation apparatus for applying at least one mark to at least one packaged item and for verifying said applied mark and for monitoring levels of compensation for said mark, said interface comprising; A pass/warning/fail indicator for indicating a result of the verification process and an image view for viewing an image of said applied mark and a data display for displaying marking data, subject of said applied mark and a stable/warning/unstable indicator for indicating the condition of the production line The invention includes an interface display for configuration of marking and verification apparatus and diagnostic set up for compensation device.

Further features of the invention are as recited in the claims herein. The scope of the invention is limited only by the scope of the claims herein.

Adva ntaes In the food and pharmaceutical industries it is essential that products are correctly marked to indicate content, manufacture audit trail and expiry date.

Manual checking of each package is not practical on high speed manufacturing lines.

Present optical validation systems in use are added to the process but do not provide feedback to the marking device to improve the quality of the mark.

More critically, present optical systems require a learning' process to recognise marks, which requires time, and remain inflexible to mark deviations which in themselves are still acceptable within the rules of packaging. Finally, present verification systems limit the speed of the manufacturing process whilst complex image capture and manipulation algorithms are processed for each individual mark.

The invention described herein closely couples the optical verification process with the marking process so that simple algorithms are used to compare the intended mark with the one actually printed. It does not limit the speed of the production process and requires no learning' phase. It is tolerant to marks within the packaging rules and is more flexible to recognise a range of marks and their frequency of change i.e. every mark could be different.

Introduction to drawings

For a better understanding of the invention and to show how the same may be carried out into effect, there will now be described by way of example only, specific embodiments, methods and processes according to the present invention with reference to accompanying drawings which: Figure 1 Illustrates schematically a prior art food label mark, comprising a company name and logo, a barcode comprising a set of parameters describing weight and price, a solid line border and a best-before-date indicating the latest consumption date of product contained therein.

Figure 2 Illustrates schematically a marking, verification and compensation machine and system according to best implementation of the present invention.

Figure 3 illustrates schematically a marking and image capture device comprising the marking and verification machine of Figure 2.

Figure 4 Illustrates schematically the segmentation of a computer stored mark and subsequent reproduction of said mark on packaging material.

Figure 5 Illustrates schematically the method of prior art image recognition and the segmentation process.

Figure 6 Illustrates schematically the process of mark segmentation of Figure 5 for verification according to best implementation of the present invention.

Figure 7 Illustrates schematically the process of mark segmentation of Figure 5 for a compensation process according to best implementation of the present invention Figure 8 Illustrates schematically a prior art food label mark indicating possible affects of printing device defects.

Figure 9 Illustrates schematically a prior art food label mark indicating poor marking device aligmnent resulting in part of the mark being illegible.

Figure 10 Illustrates schematically a prior art food label mark and a pre-printed substrate with registration marks.

Figure 11 Illustrates schematically the process of mark segmentation of Figure 5 when applied to pre-printed packages or pre-printed packaging material Figure 12. Illustrates schematically an operator interlace used to control said marking device comprising said verification device and said compensation device..

Detailed description

There will now be described by way of example the best mode contemplated by the inventors for carrying out the invention. In the following description numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent however, to one skilled in the art, that the present invention may be practiced without limitation to these specific details. Jn other instances, other well-known methods and structures have not been described in detail so as not to unnecessarily obscure the present invention.

Specific implementations according to the present invention provide for an integrated marking system with real-time optical validation and compensation:-in particular applying human readable and computer readable marks, perfonning image capture, verifring against set tolerance and compensation immediately after application of said marks.

A package is delivered beneath the marking device and a signal passed to the marking system from the packaging system, requesting a mark to be printed. The marking system produces the mark, particularly but not exclusively, using a prior art Thermal transfer printing process.

A vision system, typically a prior-art CCD (Charge Coupled Device) camera, captures multiple segments of the printed mark and a validation component compares an information content with a stored copy of the original mark used by the marking control system. Depending upon the result, a signal is passed to the packaging machine to reject the marked item or to allow the item to continue along the production process.

The same captured multiple segments of a printed mark, are further analysed by a compensation component, within the marking control system, to adjust the marking device to deliver the best possible quality whilst maximising the life of the said marking device.

Fluctuations between subsequent mark qualities are further used to indicate the stability of the production process aiding users to maximise manufacturing capacity.

There will now be described in detail, a specific marking, verification and compensation system and method of operation of the marking, verification and compensation system and a marking, verification and compensation method, according to a specific implementation of the present invention.

Referring to Figure 2. herein, there is illustrated schematically in perspective view a marking, verification and compensation system according to a first specific implementation of the present invention. The machine comprises a mounting 12071 supporting the single print head 12031 comprising: marking device 12001, image capture device 12021 and marking device compensation 1201 I. The marking control system [2081 also contains the user interface visual display unit with associated touch screen 12091.

The print head 12031 is mounted above the items to be marked 12041. Each item to be marked is presented under the head 12051, controlled by the packaging system, and printing is synchronised by the marking control system 12081 to item movement as it traverses the marking device 12001 or the item is held stationary whilst the full mark is applied 12061 to the item 12041 by a moving print head.

As the item is marked, the imaging device 12021 captures segments of the applied mark and delivers the results to the Marking central control system 12081 for analysis.

The focal length and focus of the imaging device 2021 is pre-set within the print head and requires no further adjustment in normal operation.

The marking device 12001 can be adjusted in several planes (i.e. up/down/across the width of the item/azimuth relative to the item) under the control of the marking control system 12081.

In all cases the marking, verification and compensation are carried out as an integrated process under the control of a single control system 2081.

Referring to Figure 3. herein, there is illustrated schematically in perspective view a Marking device comprising: a Prior art Thermal transfer thermal bar 13031 which positions a plurality of heating elements (pixels) 13061 arranged across the thermal bar at a pitch in excess of 300dpi and which are rapidly switched to generate pockets of heat which release the ink pigment previously bonded to the foil 13011. The foil roll 13011, containing several hundred meters of ink-impregnated foil, is supported such that the foil is threaded between the items to be printed 13001 and the Thermal bar 13031 containing the individual pixels 13061.

As the items pass beneath the thermal bar, a synchronised signal from the packaging line controller requests a marking operation. The marking device control system lowers the thermal bar so that the foil 13011 is in contact with the surface of the item to be printed 3001. The thermal bar pixels are energised and synchronised with the motion of the item and the data of the mark to be printed. The foil 13011 is also synchronised and advanced to ensure a fresh supply of ink at the thermal bar pixels 13061 throughout the marking process, with used foil being collected for later disposal 13021.

Once printing of the mark is complete, the Thermal bar 13031 is retracted away from the surface of the item being marked and the foil supply is suspended 13011. The item is then replaced by the subsequent item by the packaging line controller and the marking process repeated.

The process results in a correctly printed mark on an individual item 13041.

An imaging device 13051 is positioned as close as possible to the Thermal bar 13031 and captures segments of the printed mark as the mark traverses past the imaging device.

Referring to Figure 4. herein, there is illustrated schematically the process of dividing the original content of the mark into sections and synchronising the marking operation such that the printed mark is a facsimile of the stored original.

The mark to be printed is contained within the memory of the marking control system 14001. The mark contained in the memory is stored as a series of rasters 14021. Each raster is systematically passed to the thermal bar 14031 which contains a plurality of pixels. Under the control of the marking control system, the thermal bar heats only those pixels described by the raster such that an image of the raster 14061 is reproduced on the packaging material 14041. The marking control system synchronises passing individual rasters to the thermal bar and the pixel heating operation with the movement of the packaging substrate such that a complete facsimile of the original mark is reproduced on the packaging material 14051.

The next mark to be printed 14011 is then moved into the marking control system memory ready for the next marking operation when signalled by the packaging machine to print the mark.

Referring to Figure 5. herein, there is illustrated schematically the differences between current prior art processes of character recognition and the best practice of an implementation of this invention for the purpose of high speed verification that does not slow the production process.

First there will be by way of brief example a description of current prior art methods of character recognition. Prior art systems currently employed to verify the quality and content of a printed mark store key parameters of each character to be verified 15011. These parameters will be numerous and each parameter must be analysed against the captured image to confirm verification. The processing overhead of many computations to analyse character parameters restricts the number of marks that can be checked in a given time. This leads to a production line running below optimum capacity as the verification system analyses the mark There will now be a description of the best method of the present invention of verifying a printed mark, which does not require such extensive processing overhead and maintains a production line at full capacity.

The mark to be printed 15001 is segmented into rasters 15021. Each raster is passed to the print head and synchronised with movement of the packaging substrate 15031 to produce a facsimile of the store mark.

A copy of said mark is stored 15071 in preparation for the verification process. The imaging device 15051 captures segments of the printed mark 15061 and passes them to the verification process. The verification process 15081 compares the appropriate segments of the stored mark 15071, with those obtained from the image capture device 15061 using simple algorithms that do not require complex character recognition analysis.

Referring to Figure 6. herein, there is illustrated schematically the process of dividing the original content of a mark for the purposes of printing and capturing an image of said mark for the purpose of high speed verification that does not slow the production process.

An original mark is stored in the memory of the marking control system 16001. The said mark is systematically divided into segments of uniform size and passed sequentially to the marking device 16031. A copy of the said mark is passed to a temporary buffer 16011 within the marking contro' system.

The marking device produces a printed facsimile 6061 of the segments on the packaging material 16021. An imaging device 16041 is focused and positioned such that it scans each applied segment of the printed mark and systematically captures printed segments 605!. The captured segments are directly compared with the appropriate stored mark segments held in the temporary buffer of the marking control system 16011 by the verification process 16081. The verification process analyses the segment stored in the temporary buffer memory with the segment captured following the marking process and issues a pass or fail signal 16071 depending upon the result of the analysis. The pass or fail signal is used by the packaging machine to reject the item being packaged or allows said item to proceed along the manufacturing production line.

Referring to Figure 7. herein, there is illustrated schematically the process of dividing the original content of a mark for the purposes of printing and capturing an image of said mark for the purpose of applying compensation and improving marking device quality.

An original mark is stored in the memory of the marking control system 17001. The said mark is systematically divided into segments of uniform size and passed sequentially to the marking device 17031. A copy of the said mark is passed to a temporary buffer 17011 within the marking control system.

The marking device produces a printed facsimile 17041 of the segments on the packaging material 17021. An imaging device 17051 is focused and positioned such that it scans each applied segment 17081 of the printed mark and systematically captures printed segments 17071. The captured segments are directly compared with the appropriate stored mark segments held in the temporary buffer of the marking control system 17011 by the compensation process 17061. The compensation process analyses the segment stored in the temporary buffer memory with the segment captured following the marking process and issues compensation signals 17091 depending upon the result of the analysis. The compensation signals are applied to the compensation device 17101, which adjusts the orientation and alignment of the marking device to improve the quality of subsequent marks.

Referring to Figure 8. herein, there is illustrated schematically the effect of marking device deterioration and automatic repositioning of computer and human readable characters and barcodes to avoid damaged or worn areas to maintain the integrity of the mark.

By example, Thermal Transfer marking devices contain a plurality of heating elements (pixels) arranged singularly and uniformly across the entire width of the printing device. When new, all heating elements operate to create a facsimile 18001 of the mark stored within the marking control system. Each heating element has a finite usage where after the heating element no longer operates leading to portions of the mark which are not reproduced 18011.

By example, a barcode traverses an area of non-printing pixels, its integrity is compromised 8021 and would not be correctly scanned. Using the results from the verification process, regions of non-printing pixels are identified 18011. The marking device control system repositions the said barcode such that areas of non-printing pixels coincide with spaces within the barcode 18041. With the barcode repositioned the integrity of the barcode is maintained.

By example, a human readable date code traverses an area of non-printing pixels, its integrity is compromised 18031 and cannot not be correctly scanned. Using the results from the verification process, regions of non-printing pixels are identified 18011. The marking device control system repositions the said date code such that areas of non-printing pixels coincide with spaces within the date code 18051. With the barcode repositioned the integrity of the date code is maintained.

Referring to Figure 9. herein, there is illustrated schematically the effect of marking device misalignment and automatic compensation.

By example, Thermal Transfer marking devices contain a plurality of heating elements (pixels) arranged singularly and uniformly across the entire width of the printing device. Any variation in applied pressure along the width of the printing device, particularly from one side to the other, will result in poor thermal contact with the substrate and insufficient heat energy transferred into the ink pigment 19011.

From analysis carried out in the previously described compensation process, signals are applied to a compensation device that lowers or raises each side of the thermal printhead. The raising and lowering of the printhead, under the control of the marking control system, aligns the head with the surface being printed such that the best quality mark is obtained 19001.

Referring to Figure 10. herein, there is illustrated schematically the process of registration of a printed mark where the printed mark occurs coincident with a pre-printed mark.

A mark 110001 is stored in the marking device control system ready to print when requested by a packaging machine. The substrate 110011 to be printed upon comprises pre-pnnted marks 110021 and a registration mark 10051. The registration mark is detected by the packaging machine and used to synchronise the position of the pre-printed marks with the marks produced by the marking device 110031.

Referring to Figure 11. herein, there is illustrated schematically the process of verification of a printed mark where the printed mark occurs coincident with a pre-printed mark.

A substrate 111011 to be marked comprises of pre-printed marks 111031 and a registration mark 111021. The registration mark is detected by the packaging machine and synchromses the printing of the marking device to deliver the stored mark 111071.

An imaging device captures the pre-printed mark prior to the mark being printed by the marking device 111041. The captured image is stored within the marking device control system 111131.

Upon receiving a request by the packaging machine to print the stored mark, the said mark is systematically divided into segments of uniform size and passed sequentially to the marking device 111051. A copy of the said mark 11 1101 is combined with the previously stored image of the pre-printed mark 111131 and passed to a temporary buffer 111141 within the marking control system.

The marking device produces a printed facsimile 111091 of the segments on the packaging material 111011. An imaging device 111061 is focused and positioned such that it scans each applied segment of the printed mark and pre-printed mark and systematically captures printed segments 111081. The captured segments are directly compared with the appropriate combined stored mark segments held in the temporary buffer of the marking control system liii 4J by the verification process 111151. The verification process analyses the segment stored in the temporary buffer memory with the segment captured following the marking process and issues a pass or fail signal 111161 depending upon the result of the analysis. The pass or fail signal is used by the packaging machine to reject the item being packaged or allows said item to proceed along the manufacturing production line.

The process is repeated for each mark produced by the marking device.

Referring to Figure 12. herein, there is illustrated schematically a user display comprising a touch screen over a display, for the control and monitoring of a Marking system with optical validation and integrated compensation.

The mark being printed 112031 is presented in a window 112011. Control buttons 12041 allow the user to set Marking device parameters including the setting the pass/fail verification conditions according to the packaging rules. The results of the compensation process 112021 indicatethe degree of stability of the production line and thereby certainty of production line configuration to run at maximum yield.

Claims

Claims Claim 1. An integrated packaging marking system with

instantaneous verification and integrated compensation comprising: a marking device for applying a mark to products or their packaging; an image capture device for capturing an image of said mark: a verification device for verifying said mark; the verifying identifying regions of non-printing pixels; a compensation device to influence subsequent marks, thereby repositioning the mark such that areas of non-printing pixels coincide with spaces within the mark; and a common control system for controlling said marking device, said image capture device, said verification device and said compensation device.

Claim
2. The system as claimed in claim 1, wherein said common control system comprises a user interface.

Claim
3. The system as claimed in any one of the preceding claims, wherein said mark comprises machine readable or human readable marks or a combination of machine readable and human readable marks.

Claim
4. The system as claimed in any one of the preceding claims, wherein said verification is specified by the packaging rules for the items being marked Claim
5. The system as claimed in any one of the preceding claims, wherein, said packaging undergoes: a marking operation; and a validation operation; and a compensation operation.

Claim
6. The system as described in claim 5, wherein the speed of the production line is not limited by the validation operation.

Claim
7. The system as described in claim 5, wherein the validation operation requires no prior character recognition learning process.

Claim
8. The system as described in claim 5, wherein the validation operation allows for small character shape variations within the packaging rules.

Claim
9. The system as described in claim 5, wherein the marking operation allows for rejected marks to be subsequently repeated to maintain sequenced marking.

Claim
10. The system as described in claim 5, wherein the validation operation allows for pre-printed marks coincident with the printed mark.

Claim
11. The system as claimed in any one of the preceding claims, wherein, said packaged undergoes: a marking operation; and a validation operation resulting in an image capture of said mark; and a compensation operation resulting in the adjustment the marking device.

Claim
12. The system as described in claim 11, wherein the compensation operation adjusts the marking device alignment to produce a mark within the packaging rules.

Claim
13. The system as described in claim 11, wherein the compensation operation adjusts the marking device to extend its useful operating life whilst producing a mark within the packaging rules.

Claim
14. The system as described in claim 11, wherein the compensation operation adjusts the mark spatial position to maintain a mark within the packaging rules.

Claim
15. The system as described in claim 11, wherein the content of the printed mark may differ between one mark and another.

Claim
16. The system as described in claim 11, wherein the content of the pre-printed mark may differ between one pre-printed mark and another.

Claim
17. The system as described in claim 11, wherein the validation operation detects a mark that does not conform with the packaging rules and supplies a reject signal.

Claim
18. The system as claimed in any one of the preceding claims, further comprising: a visual display device, said visual display device configured for displaying at least one display interface.

Claim
19. The system as claimed in any one of the preceding claims, wherein, said marking device and said image capture device and said compensation device are housed within a single housing or separated into marking device and image capture device under the control of a common control system.

Claim
20. An integrated method of applying a mark to a package and verifying said mark and applying compensation to subsequent marks, said method comprising: inputting a set of data to create at least one mark; and applying said mark to at least one package or packaging; and capturing an image of said applied mark; and verifying whether said mark is within packaging rules; the verifying identifying regions of non-printing pixels; and applying compensation to marking device, thereby repositioning the mark such that areas of non-printing pixels coincide with spaces within the mark.

Claim
21. The method as claimed in claim 20, further comprising: Recording and analysing consecutive compensation parameters to establish the stability of the production process and likely probability of rejected marks.

Claim 22 The method as claimed in claim 21, further comprising: a common user interface and display providing a indication of system performance.